JPH0244400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for handling radioactive materials, and in particular to loading and removing filters used in nuclear power plants to remove radioactive impurities in primary and secondary water systems. and regarding replacement.

More specifically, the present invention can be controlled from a remote station and performs all the steps required to replace the filter and to pack the used radioactive filter into a shielded container for disposal. It relates to a device that can perform this.

In nuclear power plants, a coolant is circulated around the core of a nuclear reactor as a heat transfer medium, which transfers the heat generated in the reactor to equipment for subsequent heat transfer and/or extraction. do. Coolant branch circuits are provided and these circuits are used for a number of purposes, such as coolant volume control, coolant chemistry control, reactivity control, etc. BACKGROUND OF THE INVENTION Reactive coolant systems, associated branch circuits (commonly known as auxiliary process systems), and their associated components comprise a major portion of the fluid system of a nuclear power plant or other nuclear facility.

During the operation of a nuclear reactor or other radioactive source, foreign particles from the coolant and auxiliary process piping are carried by the coolant around the reactor core and through cooling and process equipment and piping. It circulates. As the particles flow around the radioactive source, they become radioactive and tend to accumulate at various locations in the piping system, releasing radioactive energy. Depending on the shielding associated with the piping system, radiation from accumulated particles is likely to cause health hazards to persons working within or outside the radioactive fluid system and/or components associated therewith.

In order to control the amount of foreign material flowing through cooling and process systems, nuclear power plants and other facilities are equipped with filters to collect radioactive particles that are to be removed from the coolant and process systems. an ordinary filter used to trap radioactive particles,
The housing has a top hatch through which the filter cartridge can be installed and removed from above. Cartridges with particles are typically placed in a shielded shipping container for final disposal.

The most common filtration devices in use today use disposable filter cartridges that trap radioactive solids during filtration. Such filter cartridges must be replaced periodically.

The filter cartridge is usually placed in a filter pit under the floor of the power plant and covered by a shielding plug forming the floor section. Since the filter cartridge becomes highly radioactive during use, it is placed in a shielded chamber with walls several feet thick on all sides. Removal of the used cartridge begins with removing the shielding plug, using an overhead hoist or the like, and setting the shielding plug aside to expose the filter assembly below the floor. The operator must remain behind the shield wall to avoid overexposure to the radiation produced by the filter assembly. Once the filter pit is opened, a shield drum can is placed adjacent the pit and a cartridge hook or the like is lowered into position to grab the filter cartridge. The cartridge is then pulled into and placed into a transport drum can. Once the cartridge is confirmed to be in the transport drum can, the drum can is moved from its position adjacent to the access port and transported to the processing area.

Removing and reloading the filter is very tedious and great care must be taken to protect the operator. The method and apparatus of the present invention overcome many of the difficulties described above and provide heretofore unavailable features and advantages.

It is an object of the present invention to provide a reliable method and apparatus for removing, storing and replacing filter cartridges used in nuclear power plants for disposal.

Another object of the invention is to reduce the difficulties encountered when dealing with radioactive filter cartridges that must be removed and disposed of in nuclear power plants.

The above and other objects and benefits are achieved by the novel method and apparatus of the present invention, which comprises a filter cartridge of the type placed in a shielded filter pit for treating nuclear power plant wastewater. It is about removing and replacing. The apparatus of the invention consists of a base adapted to be placed adjacent to a recess or filter pit containing a filter cartridge, and a hoist mounted above the base. The hoist includes a generally vertical column, a generally horizontal boom extending outwardly from the top of the column, and a grab device for engaging a shielding plug or filter to be transferred to or from a filter receiver or disposal drum can. , a device for remotely operating the grab, a lifting device for supporting the grab from the boom and lowering the grab through a vertical passage, and a device for remotely operating the lift device.

The apparatus also includes a drum can turret mounted in the base, which turret moves back and forth about a vertical axis spaced from the vertical passageway to a position where storage drum cans carried by the turret are located in the vertical passage. The apparatus further includes means for remotely operating the drum can turret. The device of the present invention also has a second
A turret is provided between the base and the boom for horizontal movement about the same vertical axis as the drum can turret. The second turret has at least one radially extending arm adapted to move to and from a position in line with the vertical movement path.

According to the method of the invention, a device of the type described above is operated to carry out the following steps.

(1) Place the disposal drum can on the drum turret.

(2) Place the above device in an operating position adjacent to the filter pit.

(3) Operate the lift device to lower the glove, grasp the stepped shielding plug over the filter pit, and lift the plug to its highest position; (4) until one of the arms is under the glove. Rotate the second turret.

(5) Operate the lift device to lower the grab, place the plug on your arm, loosen the plug, and lift the plug to the highest position.

(6) Rotate the second turret to its intermediate position.

(7) Operate the lift device to lower the grab, grab the used filter, and lift it to the highest position.

(8) Rotate the drum can turret and place the drum can under the used filter.

(9) Operate the lift device to lower the grab, place the used filter into the drum can, release the filter, and lift the grab to the highest position.

(10) Rotate the drum can turret to move the drum can to the removal position.

(11) Rotate the second turret and place the new filter in the vertical passage.

(12) Operate the lift device to lower the grab, grab the new filter, and lift the new filter to the highest position.

(13) Rotate the second turret to its intermediate position.

(14) Operate the lift device to lower the new filter into the filter housing, release the grab and lift it to the highest position.

(15) Rotate the second turret until the shielding plug is below the glove.

(16) Operate the lift device to lower the grab to engage the shielding plug and lift the shielding plug to its highest position.

(17) Rotate the second turret to its intermediate position.

(18) Lower the stepped shield plug to its position above the filter pit, release the shield plug, and lift the grab to its highest position.

Looking closely at the drawings, Figures 1 to 7 show a machine A that handles filters F of the type used in nuclear power plants to filter out radioactive particles in various water systems, as described above. Machine A is adapted to receive drum can D, and the used filter
F' is placed in a drum can for disposal and transported with drum can D to a predetermined location adjacent to the filter pit containing the filter F' to be removed. The drum can D is partially filled or lined with cement and defines therein a shielding recess sized to receive the used filter F'. Machine A is
Remove the drum can shielding plug P from the drum can D and replace it, remove the shielding plug from the top of the filter pit and replace it, and then remove the used filter F' from the pit and arrange it on a predetermined line in advance. Place it in the drum can. Machine A then places a new filter in the filter pit and replaces the shielding plug.

This machine uses a rotating drum can table 30.
and a carriage 10 supporting a rotatable column 40, both table 30 and column 40 rotating about the ram's vertical axis. The strut 40 has an outwardly extending boom 45 at its top, the strut and boom supporting filters F and F' and a closure plug P and a hoist mechanism 50 which can engage said shielding plug. Filter Turret 7
0 is mounted on the column 40 between the carriage 10 and the boom 45 and is rotatable to place the radially extending arm in or out of the line of travel of the hoist mechanism 50. Drum can capping assembly 100 includes placing a conventional lid L and clamping ring C over the drum can housing the filter prior to removing drum can D from the machine to complete the disposal process. After the drum can turret 30 is placed at the lid attachment position, the closing of the drum can D is completed.

The carriage 10, best seen in Figures 8, 9, 13a and 13b, has a platform 11 made of welded sheet steel and of rectangular configuration. The carriage 10 runs on four flanged wheels 12 which rest on parallel rails 13. The rail 13 is connected to one of the filter pits containing the used filter F'.
one of the filter pits so as to carry it along a sufficient travel path to place the machine in proper relation to one another.
Located parallel to a row or series.

In the illustrated embodiment, two rows of filter pits are used and the rail 13 spans both rows, so that the two filter pits can be serviced from one specific location on the carriage. . The carriage 10 is propelled by a motor 14 coupled to an axle driving a pair of wheels 12.

A pair of apertures 15, 16 are made in the front end of platform 11, which apertures accommodate two rows of adjacent filters.
It is located so that it can be in line with the pits 17 and 18. Each of the filter pits 17, 18 has a stepped shielding plug 19 which is movable by the machine A and completes the shielding of the filter F which collects radioactive particles.

A turntable 20 is provided approximately in the center of the platform 11 and is adapted to rotate about a central vertical axis. 1st
The turntable 20 shown clearly in FIGS. 3a and 13b has a circular base plate 21 bolted to a bearing ring 22 by bolts 23. The turntable 20 shown in FIGS. The bearing ring 22 is connected to the platform 1 by bolts 25.
1 is supported by a fixed bearing ring 24 bolted to 1. An external toothed ring is formed on the fixed bearing ring 24, and this external toothed ring is connected to one or both of the two motors 28, 28' provided on the base plate 21 and driven via a reduction gear unit 29. It meshes with the pinion 27 which is then driven.

Drum can table 3 on platform 11
0 is also provided, which table is adapted to move the drum can D to be disposed of between various positions during the filter replacement procedure. 12th, 13a and 1
The drum can table illustrated in figure 3b has an annular base plate 31 with a radial projection 31d supporting the drum can D. The annular base plate 31 is bolted to the bearing ring 32 by bolts 33. Bearing ring 32 is supported by a fixed bearing ring 34 which is bolted to platform 11 by bolts 35. The bearing ring 32 has an externally toothed ring 36 which meshes with a pinion 37 which rotates the annular base plate 31 . The pinion 37 is driven by one or both of the two motors 38, 38' via a reduction gear unit. Motors 38, 38' are mounted on a bracket 38a attached to platform 11.

The support 40 is located above the turntable assembly 20;
More specifically, the boom 4 is installed on an annular base plate 21 at a height suitable for creating gaps for performing the various movements required for filter replacement work.
Extends upwardly to a height sufficient to support 5. The strut 40 clearly shown in FIG. 10 has a tubular cylindrical inner member 41 welded to an annular base plate 21 and a tubular cylindrical outer member 42 coaxially with and surrounding the inner member 41. . The outer member 42 is also welded to the annular base 21, but this member only extends upwardly by about half the height of the inner member.

Outer member 42 is adapted to support filter turret 70 and is secured by gussets 43 which project radially outwardly and are welded to annular base plate 31.

At the upper end of the inner member 41 is a radial flange 44 to which a boom 45 is bolted. Boom 45 is also tightened by gussets 46.

It can be seen that the strut 40 and boom 45 rotate with the turntable assembly 20 to position the hoist assembly above either filter pit 17,18. The range of motion of turntable assembly 20 is therefore limited to openings 15 and 16 in platform 11.
It is an arc between . Normal turntable assembly 2
0 will not be moved during the filter replacement procedure once that position is initially selected.

A boom 45 extends radially outwardly from the top of the strut 40 and has steel plates welded together to form a box-shaped structure that may enclose portions of the hoist mechanism 50. and provides sufficient strength to support suspended components during the various operations performed during the filtering process.

The hoist mechanism 50 clearly shown in FIG.
It has two roller chains 51 which support a grab 55 at one end and which are fixed to a bracket 56 inside the column 40 at the other end. Grab 55
has a collet 57 which is moved between a grip position and a release position by a motor (not shown).

A roller chain 51 runs from a grab 55 to an idler sprocket 5 mounted adjacent the end of the boom.
8 and then rearwardly toward a drive sprocket 59 at the inner end of boom 45. The chain 51 extends downwardly from the drive sprocket 59 through a cylindrical space in the column 40 and connects to another idler sprocket 6 supported on a bracket 61 mounted on a counterbalancing block 62.
0, the block 62 is adapted to move vertically inside the tubular inner member 41 of the strut 40. The roller chain extends upwardly from idler sprocket 60 to bracket 56 at the top of column 40.

Balancing block 62 moves in a direction opposite to the movement of grab 55, and the grab moves twice the distance that balancing block 62 travels due to the arrangement of the chain and sprocket mechanism.

The drive sprocket 59 has two drive motors 6
4, 64' or both through the gearbox. As is the case with many operating devices of the filter removal machine A, two drive motors are provided so that the other one serves as a backup if one of them is damaged.

The hoist mechanism 50 is operable to raise and lower the grab 55 and the articles gripped thereby through a vertical passageway that engages the used filter cartridge F' in the filter pit 19. from the lower limit of a position low enough to fit, and high enough to engage the grab 55 and support the suspended article above the filter turret 70 to create a gap between the turret and the supported article. It extends to the upper limit of the position (as shown in Figure 10).

The filter turret 70 shown in FIGS.
It rests on an annular flange 71 welded to the top of the. The fixed bearing ring 72 is bolted to the flange 71 by bolts 73. A fixed bearing ring 72 is operatively associated with a rotating bearing ring 74 which supports a turret plate 75 which is secured by bolts 76. annular rim 77
is welded to the bottom of plate 75, enclosing a portion of the operating mechanism and providing a platform for limit switches and cams used in the control system. The bearing ring 74 has an external toothed ring 78 which is connected to two drive motors 8.
1, 81' or both engage a pinion 79 driven via a reduction gear unit 80. If one of the two motors fails, the other serves as a backup.

The turret plate 75 has two radially extending arms consisting of a filter arm 83 and a plug arm 84. The arms 83, 84 extend radially outwardly and rotate between neutral positions shown in Figures 1, 3, 4, 6, 7, 8 and 11, directly above the filter pit on which one of the arms is working; That is, it reaches a position where it is placed in the vertical movement path of the grab 55 (FIGS. 2 and 5). Arm 83 has a circular opening 85 for receiving a new replacement filter cartridge F and drum can shielding plug P, and supports the cartridge by a radial rim at its upper end. The arm 84 has a plug receiver 86 adapted to receive the stepped shielding plug 19.
It is equipped with

The drum can lid attaching assembly 100 is the ninth, first
4, 15, 16 and 17, once the used filter F' is placed in the drum can and the drum can shielding plug P is in place, the drum can D
This acts to tighten the lid. This assembly 100
is designed to hold the lid L and tightening ring C of the drum can, and when the drum can D is placed under the lid L and tightening ring C as shown in Figs. and the clamping ring is lowered into position and attached to the top of the drum can.

The assembly for attaching the drum can lid is cartridge 10.
A fixed base 1 provided on a platform 11 of
01. This base is an upright tubular column 10
2, which is welded to the base 101 and tightened by radially extending gussets 103. A mounting plate 104 is welded to the top of the post 102 and supports a pair of vertical guide pins 106, 107 which are removed from bearing blocks 108, 109 welded in place in the openings of the mounting plate 104. extends upward.

Mounting tool 11 for attaching the lid above the vertical column 102
0, which is supported for vertical reciprocating movement by a mounting plate 104. The lid fitting has a main plate 111 with a pair of laterally spaced vertical guide sleeves 113, 114, said guide sleeves being used for guiding the vertical movement of the lid fitting 110. It is positioned to receive pins 106 and 107.

A lead screw 115 is provided in the center of the main plate 111,
This screw is attached to the nut 11 attached to the horizontal plate 104.
It has a thread that engages with the internal thread of No. 2. The lead screw 115 is rotated via a reduction gear unit 116 provided on the main plate 111, and the reduction gear unit 116 is connected to two drive motors 117, 11.
7'. Two drive motors are provided so that if one motor fails, the other motor serves as a backup. The support rim 120 is welded to the bottom side of the main plate 111 and has an annular plate 112 attached thereto.
The annular plate 121 supports six magnets 122 at intervals in the circumferential direction, and these magnets are used to support the drum can lid L to be attached to the drum can D.

The support rim 120 also has five adjustable ring retainers 123 arranged at circumferentially spaced positions to attach the lid L to the drum can D.
It is designed to support a tightening ring C used for attaching. The rim holder 123 is supported by a bracket 124.

A pair of cam switches 125, 1 that can be activated when the drum can lid attachment fixture 110 is lowered.
26 is provided on the horizontal plate 104 and is operated by cam actuators 127 and 128 attached to the main plate 111. Switches 125 and 126 constitute part of the control system of the device.

A tightening assembly 130 is placed below the main plate 111 and is adapted to tighten the tightening ring C around the lid L and the rim of the drum can to seal the lid in place. The tightening assembly 130 is the head 1
31, the head of which is attached to the rod 132,
It is adapted to engage a tightening ring. Rod 1
32 has an external thread which engages with an internal thread of the actuating nut 134 which is driven from the gear unit 135 by one or both of the two electric motors 137, 137'. The rod 132 reciprocates tangentially relative to the clamping ring over a range of approximately 3 inches (76.2 mm) of travel.

The operation of the filter replacement machine A of the present invention is well illustrated in FIGS. 1-7.

Initially, the machine A is positioned in the workspace to receive the prealigned drum cans D, which are transported by another device, such as an overhead crane. The drum can turret 30 is first rotated to a position that provides sufficient vertical clearance to lower the drum can D onto the projection 31d. When the drum can is in this position, the tightening ring C and the lid L are removed from the drum can, and the lid attachment fixture 11 of the lid attachment assembly 100 is removed as shown in FIG.
It can be placed in 0. At this point, a new filter F is placed on the filter arm 83 of the filter turret 70. A drum can shielding plug P is also placed on top of the drum can D.

These initial steps are carried out manually, and after their completion the operator loosens the retaining screw on the stepped shielding plug 19 of the filter pit used for the operation and then avoids exposure to radiation. Therefore, move to a shielded place far away. Therefore, the filter replacement machine A operates the rail 1 by operating the motor 14.
3 into position for working on the filter pit containing the used filter F' to be removed. This is a predetermined position, for example the position taken by the carriage 10 upon actuation of a suitable limit switch located on one or both of the rails 13.

When the machine is in this position, the drum can table 30 is operated to bring the drum can onto the vertical operating path of the grab 55. The hoist mechanism 50 is then operated by the drive motors 65, 54' and the grab 55 is lowered into engagement with the pre-aligned closing plug P of the drum can D. The drum shielding plug P is lifted up and away from the drum can table 3.
0 is operated to move the drum can from the operating path,
When the filter turret 70 is operated, the filter arm 8
3 is brought into the vertical motion path. The drum can shielding plug P is then lowered onto the top of the filter arm 83 and the filter turret is operated by the motors 81, 81' to move the turret 70 out of the vertical motion path. The above operations are accomplished prior to the operations illustrated in FIGS. 1-7.

At this point, the hoist mechanism 50 is driven by the drive motor 6.
4, 64', the grab is lowered into engagement with the stepped shielding plug 19 above the filter pit as shown in dotted lines in FIG.
Lift the shielding plug 19 to the uppermost position shown by the solid line in the figure. The pit turret 70 is then operated by the motors 91, 91' to bring the plug arm 84 into the vertical movement path, after which the grab 55 moves the stepped shield plug 19 into the plug arm as shown in FIG. 84 and the turret is rotated to the neutral position.

At this point, the filter pit 17 is exposed and the radiation emanating from it creates a troubling situation, making accurate and reliable operation of the filter removal machine A extremely important.

The hoist mechanism 50 is operated to lower a grab 55 into the filter pit 17, grasping the used filter F' as shown in dotted lines in FIG. Lift the water droplet to a dry position (approx.
Hold here for 15 minutes. Next, as shown by the solid line in FIG. 3, the used filter F' is lifted to the highest position, and the drum can table 30 is rotated to the
Bring the drum can onto the vertical path as shown.
The used filter F' is then lowered into the drum can on a predetermined line as shown by the solid line in FIG. 4, and the grab 55 is released and lifted to its highest position. Drum can table 30 is operated to move drum can D to the removal position, filter turret 70 is operated to bring filter arm 83 onto a vertical path, and then grab 55 is lowered to remove drum can shielding. Grasp plug P and lift it to its highest position.

The filter turret 70 is then rotated to its neutral position, the drum can table 30 is operated to move the drum can D back onto the vertical path, and then the hoist mechanism 50 is operated to move the drum can shielding plug P out of the drum can. lower it into place inside. Drum can shielding plug P
Once in position, the drum can table 30 is operated to bring the loaded drum can D into an operating position adjacent to the drum can lid assembly 100 as shown in FIG.

At this point, the drum can lid installation work and filter replacement work can be performed, but for the present purpose, we will first describe the drum can lid installation work.
The drum can D is placed under the lid attachment fixture 110, the motors 117 and 117' are operated to rotate the guide screw 115, and the lid attachment fixture 110 is lowered onto the drum can D. Thereby, the lid L is brought to the rim of the open drum can D, and the tightening ring C is brought to a position surrounding the flange of the rim and the reinforced rim of the drum can. The clamping assembly 130 is now operated to bring the clamping ring C into a tightened position around the flange of the lid L, thus securing the lid to the drum can.

While the drum can capping operation is in progress, filter turret 70 is operated by motors 81, 81' to bring filter arm 83 onto a vertical path, and hoist mechanism 50 lowers grab 55. The new filter F is engaged as shown in dotted lines in FIG. 5 and then lifted to the highest position as shown in solid lines in FIG. The filter turret 70 is then rotated back to the neutral position (FIG. 6) and the hoist mechanism 50 lowers the grab 55 and new filter F into the filter pit 17 as shown in dotted lines in FIG. After the grab 55 is released, it is again raised to its highest position and the filter turret is operated to bring the plug arm 84 and stepped shield plug 19 onto the vertical path.

Then, the hoist mechanism 50 is operated and the grab 5
5 to engage the stepped shielding plug 19, and lift the plug to its highest position as shown in FIG. The filter turret 70 is again returned to the neutral position (FIG. 7), and the hoist mechanism 50 lowers the grab 55 and stepped shielding plug 19 onto the top of the filter pit, as shown in dotted lines in FIG. The grab 55 is released and lifted to the highest position.

The filter removing mechanism A is then propelled along the rail 13 to a position where the drum can D with a lid is lowered, and during this time the drum can table 30 is operated to separate the drum can D from the drum can lid attaching assembly 100 and vertically move it. to a position with a gap in the direction to allow removal of the filter. Drum can D is removed by an overhead gantry crane or the like and further processed for disposal.

Although the present invention has been illustrated and described with reference to specific embodiments, this is for illustration purposes only and is not intended to limit the invention, and all modifications and variations of the specific embodiments illustrated and described herein are within the scope of the invention. It will be obvious to experts in this technical field. Therefore, the invention patent is not limited in scope and effect to the specific embodiments shown and described, nor in any manner inconsistent with the scope of the advance in the art advanced by this invention. .

[Brief explanation of the drawing]

1 to 7 are partially cut-away perspective views illustrating some of the successive operating steps of the method of the invention. FIG. 8 is a plan view of the filter replacement machine of FIGS. 1 to 7. FIG. 9 is a partially enlarged cross-sectional view taken along line 9--9 of FIG. 8, with portions removed for illustration and rotated in a lidding position adjacent to the drum can lid assembly to place the drum can. The drum can table is shown below. Figure 1 is line 10-10 of Figure 8 with a portion removed for illustration purposes.
FIG. FIG. 11 is an enlarged cross-sectional view taken along line 11--11 in FIG. 10. 1st
FIG. 2 is an enlarged cross-sectional view taken along line 12--12 of FIG. Figures 13a and 13b show the 12th
FIG. 2 is an enlarged cross-sectional view taken along line 13-13 of the figure. FIG. 14 is an enlarged side view taken along line 14--14 of FIG. 8 with a portion removed and showing the drum can lid assembly. FIG. 15 is a plan view of the drum can lid attachment assembly. FIG. 16 is a partial side view taken along line 16--16 of FIG. 15 with a portion removed. Figure 17 is line 17-1 in Figure 16.
FIG. 7 is a partial cross-sectional view at FIG. 10... Carriage, 11... Platform,
13...Rail, 17, 18...Filter pit, 30...Drum can table, 31...Base,
40... Strut, 45... Boom, 50... Hoist mechanism, 51... Roller chain, 55... Grab, 59... First sprocket, 60... Second
Sprocket, 70...Filter turret, F
...New filter, F′...Used filter,
D...Drum can, P...Shielding plug.

Claims (1)

[Scope of Claims] 1. This device is for removing an old filter from a filter pit usually covered with a shielding plug P and replacing it with a new filter, and is related to a radioactive wastewater treatment system of a nuclear power plant, and is remotely controlled. a method controlled from a remote location using a device capable of engaging the shielding plug to a raised removal position with respect to the device in a vertical passageway above and centered on the filter pit; moving the shielding plug support in an arc about a vertical axis to a position below the shielding plug; lowering the shielding plug over the shielding plug support in the vertical passage; releasing the shielding plug support and the shielding plug in an arc about the vertical axis to a position out of the vertical passage; and raising the old filter relative to the apparatus in the vertical passage. engaging and lifting the old filter to a removal position; moving the disposal drum in an arc about the vertical axis to a position below the old filter; and moving the old filter into the disposal drum in the vertical passageway. moving the disposal drum in an arc about the vertical axis to a position out of the vertical path; and moving the new filter and its support along the vertical axis. moving the new filter in an arc to a position centered in the vertical passageway; engaging and lifting a new filter in the vertical passageway to a raised removal position with respect to the apparatus; and a new filter support. moving the filter in an arc about the vertical axis to a position out of the vertical passage; lowering a new filter into the filter pit in the vertical passage to release it; and shielding plug support. moving the body and shielding plug about the vertical axis to a position centered in the vertical passage; engaging and lifting the shielding plug relative to the device to a raised removal position; moving a support in an arc about the vertical axis to a position out of the vertical passage; and moving a shielding plug in the vertical passage with a filter.
lowering onto the pit and releasing it. 2. prior to said initial step of engaging and lifting the shielding plug, moving the disposal drum about said vertical axis to a position aligned with said vertical passage; engaging and lifting a disposal drum in a passageway to an elevated removal position; moving a disposal drum about said vertical axis to a position out of said vertical passageway; and moving a new filter support about said vertical axis. moving the drum shield plug in an arc to a position centered in the vertical passage; and lowering and releasing the drum shield plug in the vertical passage over the support of the new filter, thereby removing the drum shield. positioning the plug over the new filter; and, after lowering and releasing the old filter into a disposal drum, aligning the new filter support and drum shielding plug in the vertical passageway about the vertical axis; engaging and lifting a drum shielding plug in the vertical passage to a raised removal position; moving the new filter support and drum shielding plug in the vertical passageway about the vertical axis; 2. The method of claim 1, further comprising: moving the drum shielding plug in an arc to a position out of the passage; and lowering the drum shielding plug on the vertical axis to a seated position on top of the drum. 3. A remote control device for removing and replacing filters from a filter pit, comprising a base plate 21 positioned adjacent the filter pit, and hoist means 50 attached to the base plate. , the hoisting means includes a generally vertical column 40 and a generally horizontal boom 4 extending outwardly from the top of the column.
5, grab means 55 for engaging a load containing a filter being carried into and removed from the filter pit; means for actuating the grab means from a remote location; and means for moving the grab means from the boom 45. a lift means 51 for supporting and raising and lowering the grab means in a vertical passageway, and means for actuating said lifting means from a remote location, mounted on the base plate 21 and spaced apart from said vertical passageway; and a drum can table 30 for rotational movement relative to the substrate about a vertical axis spaced from the position where the storage drum D is placed in the vertical passage; and means for actuating the table 30 from a remote location. It further includes a turret 70 disposed between the base plate 21 of the column 40 and the boom 45 for horizontal movement about a vertical axis, the turret 70 being positioned in alignment with the vertical passageway and moving from this position. Apparatus having at least one radial arm adapted to be moved, further comprising means for actuating the turret from a remote location. 4 a rigid platform 11 having a substrate 21 attached thereto;
wheel means 12 adapted to engage parallel rails on opposite sides of the filter pit; mounted on the platform and operatively associated with the wheel means;
4. The apparatus of claim 3 further comprising drive means for driving the platform along the rail. 5. Apparatus according to claim 4, further comprising control means for positioning the platform in position relative to the filter pit in order to precisely align the vertical passage of the grab means with the filter pit. . 6. The substrate 21 is mounted on a platform for rotational movement about said vertical axis, and further comprising means for controlling the rotational movement of the substrate from a remote location. The device described. 7. The device according to claim 3, wherein the lifting means 51 includes chain and sprocket means. 8. The chain and sprocket means includes a series of roller chains 51 operatively connected at one end to grab means 55 and a first sprocket 58 carried at the outer end of boom 45 and operatively associated with the roller chains. a second sprocket 59 mounted on the inner end of the boom and operatively associated with the roller chain; and a second sprocket 59 operatively connected to one of said sprockets for moving the roller chain to grab the grab means 55. sprocket drive means 64, 64' for raising and lowering in the vertical passage;
8. The apparatus according to claim 7, comprising: 9 a portion of the roller chain 51 extends downwardly from said second sprocket parallel to said vertical axis and is operatively connected to said portion of the roller chain and is secured by grab means 55; 8. The apparatus of claim 7 further comprising means 62 for applying a counterbalancing load to the roller chain to balance the applied force and the load engaged on the grab means. 10 The turret 70 has two radially extending arms 83, 84, one of which supports the replacement filter and extends to and from a position aligned with the vertical passage. 4. Apparatus as claimed in claim 3, characterized in that said replacement filter is moved in an arc about said vertical axis into engagement with grab means (55). 11 Said filter pit is normally covered by a shielding plug P engaged by grab means 55, the other one of said radially extending arms 84
is configured to receive the shielding plug P from the grab means 55 and support the shielding plug, and
11. Apparatus as claimed in claim 10, adapted for movement in an arc about the vertical axis into and from a position in alignment with the grab means 55. 12. In order to fix the drum can head to the drum can D, the drum can lid attaching means 100 is adapted to receive the drum can D moved to a predetermined position by the drum can table 30. The device according to any one of items 3 to 6.